This application is for renewal of NIDA support for a study of drug use by elementary schoolchildren who live in the inner city and other nearby areas of urban Baltimore. The study is a collaborative venture of the Johns Hopkins University and Baltimore City Public Schools. The epidemiologic sample of 2400 children was recruited when the children entered first-grade in 1985-86. The study is prospective and longitudinal, with an experimental design to test two classroom interventions that may delay or reduce occurrence of illicit drug use and other problems. One intervention seeks change in socially maladaptive behavior found to be a sturdy predictor of drug abuse. To date, the children have been assessed each year since Grade 1, including two post-intervention assessments. A recent NIMH grant supports continuation of group-administered questionnaires, teacher ratings, and school record retrieval for five more years. This renewal proposal seeks to continue the NIDA-supported personal interviews on drug-related behavior, concurrent with the NIMH assessments. During the proposed study period, the children will be entering Grades 4-8, when occurrence of illicit drug use will begin to accelerate. In addition to testing for preventive effects of the two interventions, the study also will examine other factors suspected to influence the occurrence and continuation of illicit drug use. A specific focus of this examination is co-occurrence of drug use, psychiatric disturbances, and behavioral disturbances such as fighting and delinquency, as well as a set of other personal, developmental, and adaptational characteristics of the children, which are manifest in self-report measures, ratings by peers, and ratings by teachers. Periodic parent interviews are used to augment these assessments, and to strengthen the study's measurement of neighborhood and family characteristics, such as family behavior management and monitoring strategies. A pilot study is underway to test the feasibility of nesting a case-control study of illicit drug use within this prospective study design, as an epidemiologic strategy to allow intensive measurement of drug use and the conditions under which drug use occurs. Pending results from the pilot study, a companion proposal to support the nested case-control study is planned for late 1989 or in 1990. If successful, this study holds promise as an important new step in understanding risk factors and conditions that affect initiation and early development of illicit drug use. The study's experimental design and intervention plan has a specific focus on socially maladaptive behavior that might be modified to delay or reduce later occurrence of illicit drug use. However, even if the intervention has no effect on drug use, the study is designed to produce important new information on the etiology of illicit drug use and drug-related behavior.